With increasing demand for more information to be supplied to homes and/or businesses, network providers are constantly adding, expanding, upgrading, and/or switching their networks to improve overall optical communications network(s). Optical communications networks typically offer high-speed voice, video, and data transmission between users, such as providers, residential homes, businesses, government agents, and/or networks. Conventional optical networks include, but not limited to, fiber to the node/neighborhood (“FTTN”), fiber to the curb (“FTTC”), fiber to the building (“FTTB”), fiber to the home (“FTTH”), fiber to the premises (“FTTP”), or other edge location to which a fiber network extends. With increasing speed and capacity, various optical devices such as wave-division multiplexing (“WDM”) elements have been developed to manipulate optical signals, such as routing, splitting, merging, and/or dropping optical signals.
To route optical signals between various optical nodes or devices, a WDM system, for example, may be employed to handle optical signal routing. The WDM system, for certain applications, is able to multiplex a number of optical signals with different wavelengths onto a single optical fiber. A wavelength may also be referred as a frequency or a color capable of traveling across an optical fiber. Different wavelengths, for instance, can be generated by different lasers. With a WDM network environment, a typical fiber may be configured to carry multiple sets of network traffic using different traffic wavelengths. For instance, a fiber can be configured up to 88 channels wherein each channel can transmit a specific type of wavelength containing optical information.
In multiplexing of fiber optics, Arrayed waveguide gratings (AWG) are commonly used as optical multiplexers and/or de-multiplexers in WDM systems. For example, such devices are capable of multiplexing a large number of wavelengths into a single optical fiber whereby a single fiber can increase its transmission capacity considerably. The devices are based on a fundamental principle of optics and how light waves of different wavelengths can transmit information from interfering with each other. For example, if each channel in an optical communication network uses light of a slightly different wavelength from a neighboring channel, the light containing a large number of these channels can be carried by a single optical fiber with negligible crosstalk between the channels. To handle such channels, AWG's or thin-film filter (“TFF”) based WDM device can be used to multiplex channels of multiple wavelengths onto a single optical fiber at the transmission end.
A problem associated with a typical passive WDM device is optical divergence before the optical data is processed.